Novelty of iron-exchanged heteropolyacid encapsulated inside ZIF-8 as an active and superior catalyst in the esterification of furfuryl alcohol and acetic acid

Metal-exchanged dodecatungstophosphoric acids encapsulated inside ZIF-8 framework were synthesized to produce a variety of active catalysts M-DTP@ZIF-8 for the formation of furfuryl acetate from the esterification of furfuryl alcohol and acetic acid.

Thermal, mechanical, and tribological properties of short carbon fibers/PEEK composites

In this work, the effect of thermal, mechanical, and tribological properties of the blending system of different contents of short carbon fibers (SCFs) on different-viscosity poly-ether-ether-ketone (PEEK) was reported. The composites were manufactured using injection molding technique. Mechanical and tribological properties were measured by the tensile strength, the flexural strength, the coefficient of friction, and the wear rate. The results showed that the wear resistance and mechanical properties of the PEEK with the lower viscosity appeared on a more outstanding level, and experimental results showed that PEEK composites with added 10 wt% SCFs were optimal about the tribological behaviors and mechanical properties of the composites. Furthermore, based on scanning electron microscope inspections, the situation of the friction and worn surface of the material was explained.

Poly (ether ether ketone) composites reinforced by graphene oxide and silicon dioxide nanoparticles

Wear-resistant composites with excellent tribological performances and good mechanical/thermal properties were developed by blending the modification of nano-silicon dioxide (m-SiO2) and the modification of graphene oxide (m-GO) with a poly (ether ether ketone) (PEEK) matrix by twin-screw extrusion compounding and subsequently injection molding. The tribological behaviors and the mechanical/thermal properties of the composites were carefully investigated. Compared with pure PEEK, PEEK/m-GO, and PEEK/m-SiO2 composites, the PEEK/m-GO/m-SiO2 composites exhibited considerable enhancements in those performances. These were attributed to m-GO and m-SiO2 that carried the majority of the load during a sliding process and prevented severe wear of the matrix.